The Cold War
Two things have been niggling at me for a week or so. I was thinking about Anaximander’s opposites at war with one another: hot and cold, wet and dry and so on. The thought of someone living in Miletus 2500 years ago realising that “wet” and “dry” are somehow ends of a spectrum does not surprise me: presumably he saw clothes drying in the wind and water evaporating from puddles.
Today we think of hot and cold as “opposites” in some sense without giving it a great deal of thought: we associate cold with low numbers on the thermometer and hot with high numbers. But what about someone living in Miletus (average yearly temperature span only 18 Cdeg spread gently over 6 months), 2200 years before the first thermometer, 2300 years before we gained a reasonable understanding of the distinction between heat and temperature and 2400 years before the first refrigerator? I can’t see how hot and cold would be obvious ends of the same spectrum. I would have been less surprised to see “cold” at one end and, say, “soft” at the other (since colder things tend to be stiffer).
As I understand it, the only practical experiment that Anaximader carried out was to demonstrate by blowing on his hand that compressed air is cooler than non-compressed air. A totally erroneous result based on ignoring the cooling effect of the evaporation of sweat from his hand.
This raises two questions that have been niggling at me:
- What led Anaximader to believe that “hot” and “cold” were opposites?
- Did we develop a temperature scale which has cold things at one end and hot things at the other because we saw “hot” and “cold” as opposites or is that scale natural in some way?
On an unrelated note, I also learned recently that Celsius designated the freezing point of water as 100 degrees and the boiling point as 0 degrees when he introduced his scale. This might indicate that at least our association of “hotter” with larger numbers on the thermometer is fairly recent.